(1) Field of the Invention
The present invention relates to a cogeneration system having private power generating equipment for supplying power to private electricity consuming equipment, with exhaust heat of the private power generating equipment utilized for room heating and/or cooling purposes.
(2) Description of the Related Art
A conventional cogeneration system as noted above is disclosed in Japanese Patent Publication (Unexamined) No. 2-23211, for example.
In the conventional cogeneration system, exhaust gas of a two-shaft gas turbine is supplied to an exhaust heat boiler for generating hot steam. The hot steam is supplied to a condensing extraction turbine to drive a synchronous generator for generating power. Hot water is obtained from exhaust heat of the exhaust heat boiler, while cold water is obtained by supplying steam extracted from the condensing extraction turbine to an absorption refrigerator. The hot water and cold water are used for room heating and cooling purposes, respectively.
The conventional system usually employs pumps for supplying the hot water to heat exchangers for the room heating purpose, and for supplying the cold water to heat exchangers for the room cooling purpose. The pumps are driven by the power derived from the synchronous generator.
However, the above system requires numerous large capacity pumps to deliver hot water and cold water under pressure to numerous locations within a building, for example. This amounts to a disadvantage of increasing initial cost. Further, since a large amount of power is consumed in driving the pumps, the private generating equipment must have a large power output, which also increases the initial cost. On the other hand, where power is supplied from an external source, the system involves high running costs. Thus, the system tends to be expensive to install and run.